X-Message-Number: 4924
From:  (David Stodolsky)
Subject: Fwd: When does 1.40737488355328 = 0.64?
Date: Wed, 27 Sep 95 11:08: +0100


Forward of article <> () by 
 (RISKS List Owner):
Date: Tue,  Sep 95 01:00 BST-1
From:  (Ian Mason)
Subject: The latest maths bug in a Microsoft product

When does 1.40737488355328 = 0.64? When you're a user of Microsoft's Excel
spreadsheet.

For several years a (now well known) maths bug existed in the Calculator
applet that came bundled with Microsoft Windows. This remained uncorrected
in several releases over a considerable period of time.

A new maths related bug has now surfaced in another Microsoft product.
Type or paste 1.40737488355328 into a cell in a copy of Microsoft's
Excel spreadsheet and you will be rewarded, not with the number you
expect but with 0.64. If you perform arithmetic with this it will act as
if 0.64 had been entered so it is not simply a display error. When
the number is used as part of a formula the error is not apparent.

A friend who used to work in the UK investment banking business tells me
that much of the planning of the privatisation of most of Britain's state
owned industries was carried out using Excel. Perhaps we now have the real
explanation for the state of the British Economy?

The risk? Don't use software from a man who freely claims that what he
really wanted to be was a lawyer. 

Ian Mason

------------------------------

David S. Stodolsky      Euromath Center     University of Copenhagen
   Tel.: +45 38 33 03 30   Fax: +45 38 33 88 80 (C)


Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=4924